Balance



W. F. BACHMAN.

BALANCE.

APPLICATION FILED SEPT. I3. 1919;

l 235.54275, PatentedSept. 28, 19.20.

, other.

UNITED sTATss PATENT ortica.

WILLIAM F. BAC-IMAN, OF CHICAGO, ILLINOIS.

BALANCE.

Application led September-13, 1919.

0 @ZZ err/tom it may concern.' f

Be it lrnown that I, WILLIAM F. BACH- MAN, a citizen of the United States, resid-l ino' at Chicago, in the State of Illinois, haver-invented certain new and useful Improvements in Balances, of which the following is a specification.

The present invention hasto do with improvements in balances or the likegthat is, instruments for comparing the weights of articles by balancing the one against the The invention has particular reference to improvements in the construction of balances intended for comparing very light or delicate articles, screws of balance wheels for watches and the like. These screws are extremely light, some of them weighing only a fraction of a gram, and, therefore, any balance for cornparing' them must be correspondingly delicate, and accurate in its operations.

The instrument to which the present in- Vention relates is intended particularly for comparing articles such as those above mentioned, although its usefulness is not limited to this particular work. However, since it is particularly intended for comparing the timing screws for balance wheels, I will explain the instrument with particular reference to its usefulness for this work.

The timing of the balance wheel is adjusted by increasing or decreasing the weight on the periphery of the wheel, and this is generally done by the use of screws of different weights. lVhen the wheel is to be slowed down, heavier screws are to be inserted, and, on the contrary, if the balance wheel is to be speeded up, the heavier screws should be removed and lighter ones substituted. In any case, however, the screws should be balanced on the two sides of the wheel, so that it will be in perfect balance with respect to its pivotal center.V It sometimes happens that one or more screws will become lost from the periphery of the balance wheel, so that it becomes necessary to substitute other screws in order to restore the wheel to balance, and in order to properly time it.

The present scale is for the purpose of comparing these delicate screws, so that Specification of Letters Patent.

county of Cook andsuch as the timing Patented Sept. 28, 1920. serial ne; 323,568.

screws of exactly the same weight may be used in the different portions of the wheel.

In the drawings:

Figure v1 shows a perspective view of an instrument embodying the features of the present invention; and

Fig. 2 shows an enlarged detail fra-gmentary side elevation of the balance arms, the cup being shown in section so as to show the manner in which the screw sets into the cup during the comparing operations.

, I' will state that both of the figures in the drawing are on very greatly enlarged scale since the completed instrument is ordinarily only about an inch in overall direction between the two cups.

The instrument includes a base portion 4 which is relativel i heavy and substantial and is provided with the standards 5 and 6. Across the upper portions of said standards there extends a shaft or pin 7 which is journaled in the upper ends of the standards by jewels such as 8, in the usual and well understood manner. On the shaft or pin 7 is a cross beam 9 having the arms l0 and ll. The shaft 7 also carries a pointer l2 which works over the face of a scale 13 having suitable graduations, so that the condition of balance or the amount of imbalance of the beam 9 may be readily indicated on said scale.

At the ends of the arms l0 and ll are the cups 14 and 15 in which the screws or other articles to be compared are set. The beam 9 and the cups are made of any suitable material, but aluminum is found very satisfactory for this purpose, since it is light and of sullicient strength to hold its form, and can be readily worked into the desired shape.

Each of the cups la and l5 is provided with a dish-shaped or hollow recess 16 into which the article may be set. Since the screws to be compared are themselves of very light weight, and since the instrument is very delicate in its indications, it follows that in order to secure an exact comparison it Iis necessary to have the screws exactly centered in their respective cups at Vthe time the comparison is made. If the screws were simply laid in the cups, it would be evident thattlie screws v definite assnrancethat their-.centers ovgrav` the saine distance VfromY that a condition of' balance or lunbalance indicated by the pointer 12 might' or might not indicate correctly the `comparison between the screws, depending entirely upon the manner in which the screws are laid into the cups. Ii the screws lwere laid into the cups with their centers of gravity'the `Same distance from 4the pivotal Vpoint of thebeam,

and if the pointer thus indicated a Condi?" tion of balance, there would be assurance that the screwswere ofthe same weight. lf, howeven-Vt'he centers ,of gravity o-'th'e twoA screws werenotthe same distance romthe .pivotal centers ofthe beam, the comparison would :be false estaras any accuracy of sultisconcerned.- Y v Y l have, therefore, so constructed .the 'cups may be set into them with ity will be exactly the pivotal center of the beam. VFor this purpose, l have provided a perforation Iori opening ll inthe center port-ion of each cup,

whichiperforations or recesses are for the accommodation of the Shanks of ytheir respective screws. By setting screws into the cups in ythe vmanner indicated inlilig. 2 with the Vshank oi the'screw depending into or through",the-perforation or recess, Iassurance is had that therscrew lis exactly Acentered. and has its center of gravitythe `eXactcor-ieot l distance from the pivotal point ofthe beam.

hilel have herein .shown and described only afsingle .embodiment of the eatures of Vmy -invention,'still l do not limit myself to the same, except as l' may do so in the claims. p Y

I claim: I I Y l. A balance for the purpose specied comprising a beam, a pivotal Vmounting in the central portion ,of the same, a pointer in conjunction with said pivotal mounting, and

a scale in conjunction with said pointer forv the condition of balance or unration or recess orthe accommodation 'of the :shank o arsc'rew under test, substa-ntiallyfasfdescribed. Y

l2. A11 bala-nce for the' purpose specitied comprising a beam, a pivotal mounting for the same, and means in *conjunction "with said lbeam for showing cups kbeing located -equidistant from the-pivotalcenter of the beam, and each-cup having in the lower :portionof its conoavityv a down-VY Y wardly extending recess or perforation for the'accommodation of lthe, shank of4 a screw under test, substantially as described.

e wiLLiAM encuenta:

said cups be- Y the pivotal Y V cavity' with a downward-ly extending perio-k the condition or1V balance or unbalancethereof, there being v a concave cup -onleach end of the beam, -saidfU 

